diff --git a/app/assets/javascripts/discourse/lib/onebox.js b/app/assets/javascripts/discourse/lib/onebox.js
index bb282ce15..e39635bea 100644
--- a/app/assets/javascripts/discourse/lib/onebox.js
+++ b/app/assets/javascripts/discourse/lib/onebox.js
@@ -51,7 +51,8 @@ Discourse.Onebox = {
     // Retrieve the onebox
     var promise = Discourse.ajax("/onebox", {
       dataType: 'html',
-      data: { url: url, refresh: refresh }
+      data: { url: url, refresh: refresh },
+      cache: true
     });
 
     // We can call this when loading is complete
diff --git a/lib/onebox/engine/discourse_local_onebox.rb b/lib/onebox/engine/discourse_local_onebox.rb
index 7857f5555..d8bf15376 100644
--- a/lib/onebox/engine/discourse_local_onebox.rb
+++ b/lib/onebox/engine/discourse_local_onebox.rb
@@ -10,6 +10,25 @@ module Onebox
         1
       end
 
+      def self.===(other)
+        if other.kind_of?(URI)
+          uri = other
+          begin
+            route = Rails.application.routes.recognize_path(uri.path)
+            case route[:controller]
+            when 'topics'
+              true
+            else
+              false
+            end
+          rescue ActionController::RoutingError
+            false
+          end
+        else
+          super
+        end
+      end
+
       def to_html
         uri = URI::parse(@url)
         route = Rails.application.routes.recognize_path(uri.path)